JES:
I have no idea if the numbers Mike N. put up were intended to be accurate. To me, they illustrate decently how I think this would come out. It's gonna be close, but the difference in total putts would be less on the contoured greens than on the flat ones.
In any case, obviously nowhere does putt disparity get "reduced". I'm just envisioning a situation where on flat greens, it goes Ben 24, Lou 30... and on contoured it's Ben 29, Lou 34. Something like that.
So 5 is less than 6.
As for your questions, my assumption is this is over a random sampling of putts of all distances. Thus their distances from the hole would be all over the map. Average distances away? I have no idea. But I also don't see that it matters too much.
Maybe this helps: on the contoured putts, I am envisioning several instances of long ones where they after the first putt, Ben is 8 feet away, Lou is 15. They both miss, and both tap in the third. Now Ben was obviously more skillful, but the end result was that 3=3. Perhaps this would be outweighed by the instances Ben gets it to 2 feet and taps in while Lou gets it to 8 feet and 3jacks, but I don't see that... Remember the assumption also is very highly contoured putts.
I also don't see Lou four-putting enough to make this relevant....
TH